Imagine the scene of a bank robbery. The thieves have been caught red-handed in the vault by police, who have surrounded the building. So the next step is ... to let the robbers walk free amid warnings that they may be prosecuted. We're not for a moment suggesting that any crime was committed on the unzoned land surrounded by country park in Sai Kung; but there's certainly a strong case to be made that the excavation equipment on the site could only have arrived there illegally. So why is their removal being allowed without charges being filed? The three diggers have been on the site beside the Sai Wan beach on the Tai Long Wan coast for perhaps three months. It seems likely they got there by sea across the pristine sand. Yet no permit was requested or granted for the equipment to be moved to the site across protected land. Public uproar over the landowner's plans prompted work on two artificial ponds to stop on July 22. Last Friday the Agriculture, Fisheries and Conservation Department issued a permit for the equipment to be moved. There's ample evidence that a crime has been committed. Authorities have long been aware of the machinery; they even told this newspaper that no permit had been issued. Yet they don't seem in any hurry to enforce the law, which stipulates a maximum fine of HK$2,000 and up to three months in jail upon conviction. In fact, despite the case being so clear-cut, they're tight-lipped about their intentions. Dozens of pockets of unzoned land lie within our country parks. It's an anomaly that the government has to promptly correct through rezoning and, where appropriate, buy-backs. Penalties are ridiculously low and need to be updated to reflect the importance we place in environmental protection. The Sai Wan landowner has every right to do as he wishes with his site, although its use is constrained by its surroundings. Laws that prevent degradation of our precious country parks must be observed. We don't have the best record when it comes to this; and with this latest decision at Sai Wan, the track record isn't improving. Even if the fines are small, we need to take action. To ignore this responsibility sends the worst of signals. Under the terms of the permit, the owner of the diggers has two weeks to move them. But there's an alternative that would send the clearest message to people thinking of breaking the rules. Don't let the excavators leave. Let them rust.